The wear-resistant steel plate is widely used for mechanical products for use in engineering, mining, agriculture, cement production, harbor, electric power, metallurgy and the like wherein operating conditions are particularly awful and high strength as well as high wear resistance performances are required. For example, bulldozer, loader, excavator, dump truck and grab bucket, stacker-reclaimer, delivery bend structure, etc. may be mentioned.
In recent decades, the development and application of wear-resistant steel grows quickly. Generally, carbon content is increased and suitable amounts of trace elements such as chromium, molybdenum, nickel, vanadium, tungsten, cobalt, boron, titanium and the like are added to enhance the mechanical performances of wear resistant steel by taking full advantage of various strengthening means such as precipitation strengthening, fine grain strengthening, transformation strengthening and dislocation strengthening, inter alia. Since wear-resistant steel is mostly medium carbon, medium-high carbon or high carbon steel, increase of alloy content leads to increased cost and degraded weldability. These drawbacks refrain further development of wear-resistant steel.
Notwithstanding the wear resistance of a material mainly depends on its hardness, and roughness has important influence on the wear resistance of the material, too. Under complicated working conditions, good wear resistance and long service life of a material can not be guaranteed by increasing the hardness of the material alone. Adjusting the components and thermal treatment process, and controlling the appropriate matching between the hardness and roughness of low-alloy wear-resistant steel, may result in superior comprehensive mechanical performances, so that the requirements of different wearing conditions may be satisfied.
CN 1140205A has disclosed a wear-resistant steel having medium carbon and medium alloy contents, the contents of carbon and alloy elements (Cr, Mo, etc.) of which are higher than those of the present invention. This will inevitably lead to poor weldability and machinability.
CN1865481A has disclosed a wear-resistant bainite steel which has higher contents of alloy elements (Si, Mn, Cr, Mo, etc.) and poorer mechanical properties in comparison with the present invention.